New diamond interchange opens 'persistent bottleneck'

Some of the first cyclists to cross Canada's first diverging diamond interchange (DDI) at 162 Avenue South and Macleod Trail in Calgary.

By:Elizabeth Cameron/For Metro Published on

On budget, on time and the first of its kind in Canada.

It’s not often those three things can be said about the same major infrastructure project, but Mayor Naheed Nenshi and other City of Calgary officials accomplished just that at the opening of Canada’s first diverging diamond interchange (DDI) on Sunday.

Starting Monday, traffic will flow across the key interchange at Macleod Trail and 162 Avenue with some restrictions, such as a 50 km/h speed limit.

It should be completely open by October, according to the City.

“This type of infrastructure has been badly needed for many, many years,” Nenshi said at the opening. “This particular project addresses one of the most persistent bottlenecks in the city’s transportation network.”

He thanked city council, general contractor Graham Infrastructure LP and prime consultant ISL Engineering and Land Services Ltd. for getting the major project done in ‘unbelievable record time.’

The DDI concept is a relatively new design and was named one of the “100 best innovations” by Popular Science magazine in 2009.

It works by directing both directions of traffic on 162 Avenue to briefly cross to the opposite side of the bridge overtop Macleod Trail, allowing free-flowing left-hand turns both on and off of the roadway below.

According to the City, this allows better traffic flow and lets left-turning vehicles proceed without crossing opposing traffic.

It also features lanes for pedestrians and cyclists, making it easier for people from communities on either side of Macleod Trail to access surrounding businesses.

Area Coun. Peter Demong said roughly 100,000 vehicles will use the new infrastructure each day – equivalent to the population of Red Deer.

“It’s vital for the entire south end of Calgary,” Demong said. “This area has had massive growth in the last twenty years.”

Construction on the project began in 2015 and is being coordinated with the province’s Southwest Calgary Ring Road project.

The province contributed $77 million to the project, which has a total budget of $78 million.